// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_MEDIA_MEDIA_WEB_CONTENTS_OBSERVER_H_
#define CONTENT_BROWSER_MEDIA_MEDIA_WEB_CONTENTS_OBSERVER_H_

#include <stdint.h>

#include <map>
#include <memory>
#include <set>

#include "base/macros.h"
#include "content/browser/media/session/media_session_controllers_manager.h"
#include "content/common/content_export.h"
#include "content/public/browser/web_contents_observer.h"

#if defined(OS_ANDROID)
#include "ui/android/view_android.h"
#endif // OS_ANDROID

namespace device {
class PowerSaveBlocker;
} // namespace device

namespace media {
enum class MediaContentType;
} // namespace media

namespace content {

// This class manages all RenderFrame based media related managers at the
// browser side. It receives IPC messages from media RenderFrameObservers and
// forwards them to the corresponding managers. The managers are responsible
// for sending IPCs back to the RenderFrameObservers at the render side.
class CONTENT_EXPORT MediaWebContentsObserver : public WebContentsObserver {
public:
    explicit MediaWebContentsObserver(WebContents* web_contents);
    ~MediaWebContentsObserver() override;

    // Called by WebContentsImpl when the audible state may have changed.
    void MaybeUpdateAudibleState();

    // WebContentsObserver implementation.
    void WebContentsDestroyed() override;
    void RenderFrameDeleted(RenderFrameHost* render_frame_host) override;
    bool OnMessageReceived(const IPC::Message& message,
        RenderFrameHost* render_frame_host) override;
    void WasShown() override;
    void WasHidden() override;

    bool has_audio_power_save_blocker_for_testing() const
    {
        return !!audio_power_save_blocker_;
    }

    bool has_video_power_save_blocker_for_testing() const
    {
        return !!video_power_save_blocker_;
    }

protected:
    MediaSessionControllersManager* session_controllers_manager()
    {
        return &session_controllers_manager_;
    }

private:
    void OnMediaDestroyed(RenderFrameHost* render_frame_host, int delegate_id);
    void OnMediaPaused(RenderFrameHost* render_frame_host,
        int delegate_id,
        bool reached_end_of_stream);
    void OnMediaPlaying(RenderFrameHost* render_frame_host,
        int delegate_id,
        bool has_video,
        bool has_audio,
        bool is_remote,
        media::MediaContentType media_content_type);

    // Clear |render_frame_host|'s tracking entry for its power save blockers.
    void ClearPowerSaveBlockers(RenderFrameHost* render_frame_host);

    // Creates an audio or video power save blocker respectively.
    void CreateAudioPowerSaveBlocker();
    void CreateVideoPowerSaveBlocker();

    // Releases the audio power save blockers if |active_audio_players_| is empty.
    // Likewise, releases the video power save blockers if |active_video_players_|
    // is empty.
    void MaybeReleasePowerSaveBlockers();

    // Helper methods for adding or removing player entries in |player_map|.
    using PlayerSet = std::set<int>;
    using ActiveMediaPlayerMap = std::map<RenderFrameHost*, PlayerSet>;
    void AddMediaPlayerEntry(const MediaPlayerId& id,
        ActiveMediaPlayerMap* player_map);
    // Returns true if an entry is actually removed.
    bool RemoveMediaPlayerEntry(const MediaPlayerId& id,
        ActiveMediaPlayerMap* player_map);
    // Removes all entries from |player_map| for |render_frame_host|. Removed
    // entries are added to |removed_players|.
    void RemoveAllMediaPlayerEntries(RenderFrameHost* render_frame_host,
        ActiveMediaPlayerMap* player_map,
        std::set<MediaPlayerId>* removed_players);

    // Tracking variables and associated power save blockers for media playback.
    ActiveMediaPlayerMap active_audio_players_;
    ActiveMediaPlayerMap active_video_players_;
    std::unique_ptr<device::PowerSaveBlocker> audio_power_save_blocker_;
    std::unique_ptr<device::PowerSaveBlocker> video_power_save_blocker_;

    MediaSessionControllersManager session_controllers_manager_;

    DISALLOW_COPY_AND_ASSIGN(MediaWebContentsObserver);
};

} // namespace content

#endif // CONTENT_BROWSER_MEDIA_MEDIA_WEB_CONTENTS_OBSERVER_H_
